The KEYBOARD is the most widely used input
peripheral device in computer systems. It is simply a typewriter
except that it has certain keys that send special meanings to the terminal
or computer. There are two basic types of keyboards, the
Alphanumeric Keyboard and the Special Function Keyboard.

ALPHANUMERIC KEYBOARDS

Also known as the QWERTY keyboard (named for
the first raw of letter keys). They contain 101 standard keys which
are the following :? Alphanumeric Keys — Alphanumeric is a fancy term
for “letters and number.” This area of the keyboard also includes
a Shift key for upper case letter, an Enter key, a Spacebar, a Tab key
and a Backspace key.? Function Keys — The function keys are the 12
F keys at the top or left side of the keyboard. These keys are numbered
F1, F2, F3, and so on. They are used for entering commands.? Arrow Keys — Also known as the cursor–movement
keys, the arrow keys move the cursor around on–screen.? Numeric Keypad — It consists of a group of number
keys positioned like the keys on an adding machine. This keypad includes
a Num Lock key. With Num Lock turned on, one can use the keypad to
type numbers. With Num Lock turned off, the numeric keypad works
just like the arrow keys.? Ctrl and Alt Keys — The Ctrl (control) and Alt
(Alternate) keys make the other keys on the keyboard act differently from
the way they normally act.? Esc Key — Escape key is used to back out or quit
whatever program one is currently on.

SPECIAL FUNCTION KEYBOARDS These keyboards are designed for specific
applications to enable rapid interaction with the computer system.
Some of these types contain icons rather than alphanumeric symbols such
as those used in fast food restaurants where the icons represent food items.
Also available are keyboards for foreign languages or those that include
scientific characters.